A second species of Tyloceridius Malaise (Hymenoptera, Tenthredinidae)

Abstract Tyloceridius Malaise, 1945 and T. dorsatus (Mocsáry, 1883) are redescribed. Tyloceridius stictocephalus sp. n. from China and Nepal is described. Tyloceridius is recorded in China for the first time.


Introduction
described the monotypic Tyloceridius from Kashmir and the Himalaya and designated Allantus dorsatus Mocsáry, 1883 as the type species, with Rhogogastera bituberculata Cameron, 1906 placed as a junior synonym. Since then, Muche (1983) recorded this species from India (Uttaranchal), and Togashi (1989) from Pakistan (Islamabad). Saini et al. (2006) listed the provinces Himachal Pradesh, Jammu and Kashmir, and Uttaranchal for the distribution in India. Saini (2007) redescribed the genus and both sexes of the species and illustrated the lancet, penis valve and gonoforceps. No further species of the genus was hitherto known (Taeger et al. 2010).
During a survey of the sawfly fauna of Tibet in the summer of 2003, a specimen of Tyloceridius was collected at Yadong. The examination of the lectotype of T. dorsatus showed that the specimen from Tibet belongs to an undescribed species. Later, a series of the new taxon from Nepal was found in unidentified material at the SDEI.
The images were obtained using a Leica S8APO digital camera and Motic BA400 microscope and further processed with Helicon Focus 5.1(©HeliconSoft) and Adobe Photoshop CS6 software. The images based on specimens from Nepal were taken at the DEI with a Leica DFC 495 digital camera and M205 C microscope and processed with CombineZ5.3 and PhotoImpact X3.
Abbreviations used are: OOL = distance between the eye and outer edge of lateral ocellus; POL = distance between the mesal edges of the lateral ocelli; OCL = distance between a lateral ocellus and the occipital carina or hind margin of the head; ED = the ratio of the distance between anterior-lower corner of eyes and the greatest diameter of an eye. CSCS = Central South University of Forestry and Technology, Changsha, P. R. China; SDEI = Senckenberg Deutsches Entomologisches Institut, Müncheberg, Germany; HNHM = Hungarian Natural History Museum, Budapest, Hungary; NHRS = Naturhistoriska riksmuseet, Stockholm, Sweden; NKME = Naturkundemuseum Erfurt, Germany; USNM = National Museum of Natural History, Washington D. C., USA.

Diagnosis.
Distinguished from other genera of Tenthredininae by deep furrow on ventral side of antennal flagellum and the very large, protruding and isolated supraantennal tubercles. Description. Body robust (Figs 1, 8). Clypeus transversely subconvex at basal third, anterior margin sharp, quarter-circularly incised with acute lateral teeth; apical third of labrum deflexed, and labrum thus truncate at apex in front view (Figs 5,11); mandibles strongly bent at apical third, asymmetric (Figs 2, 3), right one with 1 basal tooth, 3 inner teeth; one of them placed on the dorsal side (Fig. 3); left mandible with 1 basal tooth and 2 inner teeth, without dorsal tooth (Fig. 2); malar space longer than diameter of median ocellus; inner margins of eyes very feebly S-curved and converging downwards, distance between eyes much longer than height of eye (Figs 5, 11); supraantennal tubercles large, highly elevated and quite free-standing (Figs 4, 10, 12); head elongated behind eyes, occipital carina low but distinct; interocellar furrow broad and deep, postocellar furrow broad and shallow. Antennae stout and uniformly thick; 2 nd antennomere about as long as broad, flagellum with a very deep and sharp longitudinal furrow along the outer-side from apex of the 3 rd antennomere to 9 th antennomere, 3 rd antennomere distinctly longer than 4 th (Figs 6,9). Anterior lobe of pronotum broad, without marginal carina, with broadest part about 3 × diameter of an ocellus; ventral margins of propleura narrowly but distinctly meeting; mesoscutellum flattened, mesoscutellar appendage with an obtuse middle ridge. anterior basin of metascutellum narrow, furrow like; dorsal lobe of metepimeron long and linear; mesosternal thorns wanting; posterior corner of metepimeron round, without appendage. Basal plates (first tergite) of abdomen contiguous on meson, without large membranous blotch (Fig. 8). Inner tibial spur of fore leg bifurcate at apex; hind coxa small, hind femur not reaching apex of abdomen, distinctly shorter than hind tibia, hind tibial spur shorter than half length of metabasitarsus; metabasitarsus about as long as or slightly longer than following 3 tarsomeres together; claw cleft, inner tooth shorter than outer tooth. Venation similar to Tenthredo, anal cell of forewing with a short and erect cross vein at basal 2/5; hind wing with 2 closed middle cells, anal cell sessile or shortly petiolate (Figs 1, 8).

Key to species
1 Dorsal side of head strongly shiny, with few widely scattered punctures; postocellar area not distinctly more strongly punctured than lateral parts of vertex; in both sexes, posterior yellow margins of tergites 3-4 not broader medially than laterally, usually connected with lateral yellow band of abdomen . Description. Holotype ♀ (Fig. 1). Body length 11mm. Greenish yellow, following parts black: apex of each mandible; antennae entirely; supra-antennal tubercle, frons and adjacent area of upper inner orbit except a stripe on frontal ridge, postocellar area, a broad band from upper hind corner of each eye to postocellar area (Figs 1, 4); a medial band on pronotum; meso-and metanotum, except mesoscutellum and 2 small triangular spots on mesoscutal lateral lobe and 2 linear spots on mesoscutal median lobe; abdomen above, except for tergites 8-10 and a broad band on posterior margin of tergites 3-4 (in the middle covering about two thirds, laterally about one third of the length of the tergite); depressed upper corner of mesepimeron and a minute and roundish dot in lower posterior corner of mesepisternum. Legs greenish yellow, following parts black: a small dot on extreme apex of each femur; a narrow dorsal stripe on each tibia and tarsus. Wings hyaline with very faint yellow tinge, vein C and stigma yellow brown, other veins pale brown. Body hairs silver.
Body shiny; labrum without large punctures; central area of clypeus, outer sides of mandibles with some large punctures, head above antenna including supra-antennal tubercle with large and deep punctures, interspaces between punctures about as large as a puncture, surface smooth and shiny; punctures on postorbit sparser but distinct; punctures on mesoscutal median lobe and mesoscutal lateral lobe smaller than punctures on head, interspaces shiny; posterior margin of mesoscutellum densely punctured, dorsal side of mesoscutellum hardly punctured; mesoscutellar appendage impunctate, parapsis of mesothorax microsculptured; metascutellum with some minute punctures; mesepisternum densely punctured, narrow interspaces smooth, strongly shiny; metepisternum densely punctured, mesepimeron and metepimeron polished, with scattered punctures. Abdominal tergites 1-2 strongly shiny, tergite 3 weakly microsculptured in basal half, tergites 4-7 distinctly microsculptured and punctured in basal half.
Variability (females). Body length 10-11 mm. Punctation on upper head varies from sparse to dense; supra-antennal tubercle sometimes only with few punctures and / or smaller than scape; tergites 1-2 smooth to rather densely punctured laterally and on basal half; POL : OOL : OCL = 1 : 2.0-2.7 : 2.0-2.6; postocellar area 1.2-1.4 × as broad as long; head behind eyes 0.8-1.0 × as long as eyes in dorsal view. Ratio of length and breadth of antennomeres 6-8: 1.5-1.9. Black spot on lower mesepisternum may be indistinct or missing; pale color on tergite 4 may be reduced to a triangular spot; greenish color may alter (in dried specimens) to yellow.
Male. (Figs 8-10) Body length 8-9 mm. Color and structure similar to female. Generally darker than the female: pale stripe on upper inner orbit very narrow and only exceptionally nearly extending toward postocellar area; frontal ridges black or pale marked; hind tibia and tarsus entirely black; pale macula on mesoscutellum more or less reduced; mes-oscutal median lobe usually entirely black, without pale lateral stripe; tegula black, basally pale; lower mesepisternum usually with broad black stripe, sometimes anteriorly reduced to a large spot; tergites 3-4 dorsally usually only with faintly indicated pale hind margin, sometimes completely black; subgenital plate apical margin rounded. Penis valve Fig. 10.
Pictures of several paratypes are given in original resolution at doi: 10.6084/ m9.figshare.781286 Etymology. The specific epithet, an adjective, refers to the distinctly punctured head.  Description. Lectotype of A. dorsatus ♀ (Fig. 11), additions based on other specimens are given in brackets [ ].
Body length 11 mm. Greenish yellow, following parts black: apex of each mandible; antennae entirely (Fig. 14); supra-antennal tubercle, frons and adjacent area of upper inner orbit except a short stripe on frontal ridge, postocellar area, a broad band from upper hind corner of each eye to postocellar area (Figs 12, 13); a medial band on pronotum; meso-and metanotum, except mesoscutellum and 2 small triangular spots on mesoscutal lateral lobe and 2 linear spots on mesoscutal median lobe (the latter sometimes absent); abdomen above, except for tergites 8-10 and posterior 2/5 of tergites 3-4; depressed upper corner of mesepimeron and a small and roundish spot in lower posterior corner of mesepisternum. Legs greenish yellow, following parts black: a small dot on extreme apex of each femur; a narrow dorsal stripe on fore and middle tibiae, dorsal side of hind tibia; a narrow stripe on fore and middle tarsi above (sometimes interrupted), hind tarsus entirely. Wings hyaline with faint yellowish tinge, veins and stigma pale brown, base of stigma slightly darkened. Body hairs silver. Body shiny; labrum and outer side of mandible with some large punctures, head otherwise almost impunctate, frontal basin feebly microsculptured; mesoscutal median lobe and mesoscutal lateral lobe sparsely punctured, interspaces smooth and shiny; posterior margin of mesoscutellum densely punctured, dorsal side of mesoscutellum hardly punctured; mesoscutellar appendage and parapsis impunctate; metascutellum with some minute punctures; mesepisternum shallowly but distinctly punctured, surface smooth, strongly shiny; metepisternum densely punctured, mesepimeron and metepimeron polished, with scattered punctures. Abdominal tergites 1-2 strongly shiny, tergite 3 weakly microsculptured in basal half, tergites 4-7 distinctly microsculptured and punctured in basal half.

Discussion
The two species of Tyloceridius are very similar, and as T. stictocephalus seems to be also rather variable in sculpture and color, the species are to be identified by consideration of the character sets given in the key. The genitalia of the taxa are not suitable for identification. According to the present data, T. dorsata seems to be a species from the western Himalayas, whereas T. stictocephalus is hitherto only known from the central Himalayas.
The type of Rhogogastera bituberculata Cameron, 1906 could not be found in the course of the present study. Cameron's description disagrees in several aspects with T. dorsatus and T. stictocephalus. But as Malaise (1945) synonymized the taxon after examination of the types of A. dorsatus and R. bituberculata, and we could not find any other specimens that fit with Cameron's description, we assume that Malaise's synonymization is correct. This is supported also by the type locality (Kashmir, western Himalayas). Goulet (1996) considered Tyloceridius to be the sister group of Rhogogaster Konow, 1884. This is based on three shared derived characters (green color, not expressed submarginal furrow of the pronotum, and very narrow apical lobe of the metepimeron). Currently, there is no additional evidence to support this hypothesis. The only available COI barcode for Tyloceridius (DEI-GISHym 17228, BOLD:ACG2198) is rather distant (about 10 %) from its nearest neighbors Tenthredo aaliensis (Strand, 1898) and Tenthredo xanthoptera Cameron, 1876), while the distance to Rhogogaster species is about 13-14 %.